JP2010260078A5 - - Google Patents

Claims (6)

A burring method for performing burring on a plate-shaped workpiece without forming a pilot hole in advance,
(A) A plate-like workpiece is sandwiched between a punch die and a die die, a pressure protrusion provided in the punch die, and a pressure protrusion provided in the die mold so as to face the pressure protrusion. The portion clamped and pressed is formed into a thin wall by pressing and pressing, and the metal of the portion to be pressed and pressed is formed around the pressurizing protrusion provided in the punch mold or die mold. Flow into the annular recess that is formed, forming a cylindrical protrusion on one side of the upper surface or the lower surface of the workpiece and forming a recess on the other side of the workpiece;
(B) a step of punching out a thinned portion that has been pressed and pressed by the pressing protrusions of the punch die and the die die;
A burring method characterized by comprising: A burring method for performing burring on a plate-shaped workpiece without forming a pilot hole in advance,
(A) A plate-like workpiece is sandwiched between a punch die and a die die, a pressure protrusion provided in the punch die, and a pressure protrusion provided in the die mold so as to face the pressure protrusion. the clamping pressure portions by projecting into the punch tool to comprise a burring portion forming the recess, and thereby form a thinner nipped圧加, the metal portion is pressed the clamping圧加, radiation outward flows into, on surfaces of the workpiece, the step of forming a concave portion on the other side of the workpiece to form a cylindrical protrusion,
(B) a step of punching out a thinned portion that has been pressed and pressed by the pressing protrusions of the punch die and the die die;
A burring method characterized by comprising: 3. A mold used in the step (a) in the burring method according to claim 1, wherein the mold includes a punch mold and a die mold, and the punch mold includes a punch head at an upper end portion. A plate having a through hole in which a lifting body having a pressure projecting portion at a lower end portion is vertically movable and urged downward in a cylindrical punch guide, and the pressure projecting portion penetrates vertically. The pressing member is provided at the lower end of the punch guide, and the lower surface of the plate pressing member is provided with an annular recess surrounding the pressurizing protrusion, and the die mold is provided in the punch mold. A die having a pressurizing projection facing the pressurizing projection on the die body, and an ejector plate that is movable up and down and biased upward around the pressurizing projection. . 4. The mold according to claim 3 , wherein a tip surface of the pressurizing protrusion in the punch mold is formed into a convex curved surface, and a tip surface of the pressurizing protrusion in the die mold is A mold having a concave curved surface corresponding to a convex curved surface.   A die used in the step (a) in the burring method according to claim 1, comprising a punch die and a die die, and the punch die is provided at an upper end portion in a cylindrical punch guide. A punch body having a pressing projection that can be protruded downward from the punch guide, and is provided with a punch body that can be moved up and down and urged upward. An ejector plate is provided around the upper protruding portion of the main body so as to be movable up and down and biased upward. A mold having an annular recess around the pressure protrusion provided. 6. The mold according to claim 5 , wherein an upper surface of the pressing protrusion in the die mold is formed at the same height as the upper surface of the upward protrusion or lower than the upper surface of the upward protrusion. A mold characterized by that.